High performance imide polymers are characterized by excellent thermal stability, solvent resistance and high glass transition temperatures (Tg). U.S. Pat. No. 7,015,304 and RE43,880 (both Chuang), the disclosures of which are incorporated by reference, disclose the preparation by a batch process of solvent-free, low-melt imide oligomers and thermosetting polyimides, and to the process of preparing such oligomers and polyimides.
U.S. Pat. No. 6,066,710 (Becker et al.) discloses an extrusion process for making aromatic polyimides from symmetrical dianhydrides.
Also U.S. Pat. No. 8,093,348 (Chuang), the disclosure of which is incorporated by reference, discloses a variety of starting asymmetric dianhydride monomers, diamine monomers, and endcap monomers useful for making aromatic polyimide polymers.
None of these prior efforts has addressed the particular and peculiar requirements for polymerizing monomers to yield new aromatic polyimides which are suitable for use in 3D printing.
3D printing (also known by the other phrases identified above) is being hailed in the polymer industry as a new means of forming shaped polymeric articles, literally from the ground up. Like soldering, a space is filled by a material coming from a filamentary form and being heated for delivery precisely to the x-y-z coordinates of that space. A lattice or scaffold of supporting material is also often delivered to adjoining spaces in the same precise manner to fortify the polymeric material of the shaped, printed article until that polymeric material sufficiently cools to provide a final rigid structure in the desired shape, which can be separated from the supporting material.
The polymeric material considered for use in 3D printing has included customary semi-crystalline polymers but has recently also focused on polymer resins and blends of polymer resins which have high temperature performance properties. Aromatic polyimide has been considered a candidate for use in 3D printing.